When Tommy Jordan came across a Facebook post written by his teenage
daughter complaining about how she had to do chores, he decided to film
his response and upload it to YouTube:

This dramatic situation started when Jordan discovered a Facebook
post from Hannah, complaining about her daily life at home. The note,
which Jordan read and analyzed in his sit-down chat with the camera,
takes issue with the slew of chores she’s forced to do each day.
“To my parents: I’m not your damn slave,” the note
begins. The teenage angst bleeds from the note, as Hannah proposes that
her parents pay her for the chores that she does. This point, in particular,
sets off Jordan, an IT worker from Albemarle, N.C., who proceeds to
delineate how entitled Hannah sounds in the note. But that wasn’t
the only punishment he planned for his daughter’s supposedly “hard”
life.

“That right there is your laptop,” he explains, filming
the newly-upgraded computer perched vulnerably in the grass. “This
right here is my .45.” A quick cock of the gun, and Hannah’s
laptop takes a shot through the screen. In the next 30 seconds, he proceeds
to empty his gun, and the bullets shatter the computer’s plastic
shell.

Are you seriously asking us whether it's justified to break someone's possessions when they say something you dislike?

1. This kind of incommensurate response is never justified;2. The amount of time between the discovery and the breaking renders impossible the chance that it was an excusable instance of uncontrollable anger;3. It sets a bad example.

That's way over the top. She didn't say it to his face, she didn't argue it at him, just vented in a way all 15 years old do - in a diary (albeit a public one)

Also he's probably going to be stuck buying another computer in the near future. All her homework probably needs to be typed up or research. He's being overly dramatic without any foresight, which is a very 15 year old child like thing to do.